Ecotourism promotes responsible travel to natural areas, environmental conservation and the well-being of local communities. Eco-lodges are an important component of ecotourism ventures but an infrequently researched component of this field. Considering their influence on the natural environment (design and operation) and local communities (employment practices and purchases), the success of ecotourism depends, in part, on the performance of eco-lodges. This project studies the effects of the Punta Islita (PI) eco-lodge on the Nicoya Peninsula, Costa Rica. An interdisciplinary nested-scale analysis, combining guest and household interviews with multi-temporal remote sensing analysis of forest cover change of the lodge and surrounding areas, is used to evaluate the environmental, economic and social impacts of ecotourism in the region. Our results show significant positive contributions of the PI eco-lodge on forest cover, environmental conservation, and local economic incomes within the surrounding communities. For local livelihoods, the PI eco-lodge was seen as having positive social, cultural and economic impacts for nearly all societal variables for both employees and their neighbours. The PI eco-lodge was also perceived as reducing alcoholism, drug addiction and prostitution, where conventional tourism on the Peninsula was shown to increase these ‘societal ills’. Land value and product pricing were the few variables believed to have increased as a result of tourism on the Peninsula. For conservation, the PI eco-lodge property had the highest rates of reforestation within the Nicoya Peninsula and remains the scale most reforested in both forest cover change and total forest cover. In fact, at the landscape scale, we find that the Pacific coast of the Nicoya, where the bulk of ecotourism occurs, has undergone reforestation, whereas forest interiors have been deforested. Historically, reforestation occurred as cattle ranching credit programs were halted by the government and households in the area left to find better job opportunities. The PI eco-lodge, as a source of good employment, resulted in worker migration back to the surrounding area, resulting, in some cases, in increased deforestation. Overall, we feel that the PI eco-lodge serves as an example of successful ecotourism. However, increasing development in the region, in particular by standard hotel operations and large condo developments, seeks to capitalise on the region's natural beauty and may reverse land cover trends if they are not accompanied by adequate forest conservation strategies and stresses the importance of monitoring and assessing the impacts of accommodations tied to nature-based tourism operations. Copyright © 2010 John Wiley & Sons, Ltd.